Aircraft gun mount mechanism



Aprii 8 E. LANCIANI 2,237,833

AIRCRAFT GUN MOUNT MECHANISM- Filed Aug. 2, 1938 2 Sheets-Sheet l Tifii.

nil lllll I INVENTOR:

amb xmocm BY W M ATT oRNEY S.

April 8, 1941.

E. LANCIANI I 2.237.833 AIRCRAFT GUN MOUNT MECHANISM Filed-Aug. 2, 1938-2 Sheets-Sheet 2 F13. EL.

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Patented Apr. 8, 1941 AIRCRAFT cum MOUNT MEG 1;

Ettore Lanclani, Milan, Italy, assignor to Aeroplani Caproni SocletaAnonima, Milan, Italy Application August 2, 1938, Serial No.

In Italy August 4, 1937 2 Claims.

This invention relates to the training of guns on aircraft. The objectof the invention is to afford a means for neutralizing the aerodynamicthrust exerted during the flight on the surface of guns or fire-armscarried on board of airplanes or other aircraft. The invention furtherafi'ords the result of reducing the turning moment, relatively to theaxis of rotation of the weapons turret, due to the usual dissymmetry ofthe surfaces exposed to the relative wind. The aerodynamic thrust ofsaid relative wind is a serious obstacle to the training of the guns onboard an airplane, as it interferes with the aiming and compels themachine-gun attendant to take it into account and to check it. Saidthrust is proportional to the area of the surface exposed to the streamof air, the effective surface varying according to the direction inwhich the weapon is trained and according to the direction of the axisof the machine, which causes diiiiculties for the gunner in taking aimand to reckon and check said thrust. Besides, the outwardly projectingpart of the gun is subject to a Varying moment relatively to the axis ofthe turret, causing unbalanced stress on the latter in variousdirections according to the direction in which the gun or the guns arefiring.

The present invention solves the problem of eliminating almost entirelysaid unbalanced thrust upon the weapon and therefore the resultingmoment, affording, for any direction in which the guns may be swung aneasy and ready training of the same and as well ease in rotating thewhole turret about its axis.

The fundamental principle of the present invention is that ofcoordinating with the gun or firearm a conjugate surface capable ofreceiving a wind thrust always substantially balancing that acting onsaid gun itself, so that the latter is subject to two moments ofrotation, practically equal in value, but acting in opposite directions.

In one form of embodiment the invention has a wing movable on the rotaryturret and exposing an area of its surface which varies with thedirection of the swing of the gun so that the wind pressure on the wingmay be converted into a force which is applied to the weapon in such away as to obtain a swinging moment substantially opposed to that causedby the aerodynamical thrust on the weapon itself.

The conjugated surfaces of the gun and wing always stand in suchpositions as to neutralize the dead-swing tendency of the weapon, notonly around a vertical or horizontal axis but around any other axis.

In the preferred embodiment shown, the conjugate or wing surfaceconsists in a surface havingv a shape generally similar to that of theweapon used and whose motions are determined Fig. 1 is a perspectiveview of an aircraft turret and gun thereon with added means embodyingthe present invention.

Fig. 2 is a side elevation thereof, partly in ver- I tical section.

Fig. 3 is a vertical section taken on the line 3-3 of Fig. 2.

The drawings show the machine gun or other firearm it which may be ofconventional form with or without a cooling case as shown in Fig. 1. Theneutralizing means of this invention comprises a swingable wing memberII, which is in the nature of a dummy or member having a general shapeand size similar to that of the gun, although if desired it mightconstitute a secondary un, so long as it presents the conjugate windsurface of this invention. The gun is shown mounted to swing up or downabout a conventional shaft l2, while the wing or balancer similarlyswings about a. shaft or axle l3. The gun and the balancer protrudeoppositely but to a similar degree from their preferably symmetricalmounting upon the aircraft turret.

In order that the balancer may have always the corrmponding movements tothose of the gun, but in substantially symmetrically oppositedirections, the two are shown mechanically interconnected for thepurpose, this being indicated as being accomplished by means of a gearor toothed segment It on the gun shaft l2 and a similar segment gear I 5on the balancer shaft l3, the two in mesh. By this arrangement, when thegun is swung upwardly, so is the balancer. On the other hand when theturret is rotated to swing the gun in one direction in respect to thewind, the balancer by the rotation of the turret swings in the oppositedirection.

By these arrangements the gun and balancer are cperatively coupled inconjugate relation so that the force of the wind thrust onthe balanceror wing in either direction is transmitted and impressed as a turningmoment or torque upon the sun, and this stress or torque is always insubstantially balancing opposition to the stress or torque existing atany moment in the gun as impressed directly on the gun by .the relativewind; and this action continues throughout all varying positions of thegun and the wing.

The remainder of the illustrated apparatus .may be described as follows.The gun and balancer are shown mounted on an upright turret wall It,which may extend substantially across the diameter of the turret H. Inits rotation the turret runs upon a fixed track l3 suitably mounted inthe aircraft, preferably with rollers for ease of motion.

' The gunners control of the turret and gun may be through the followingmechanism, of generally conventional character. On the fixed track I3 isshown an internal gear i9, and meshing with this fixed gear I9 is a gear20 carried on the turret, so that by turning the gear 20 the turret maybe progressively rotated. By a bevel gear 2| on the gear 20 and ameshing bevel gear 22 on a shaft 23, motion may be communicated to theturret gearing. The shaft 23 is shown with universal joints near itsrespective ends, and this system of parts may have conventional bearingsmounted-on the turret or its wall 16 but omitted for clearness ofshowing.

In the case of manual operation the shaft 23 may carry a sprocket wheel24 connected by a sprocket chain 25 with a sprocket wheel 28 mounted onthe same stubshaft as an operating handwheel 21. Thereby rotation of thehandwheel operating through the described train of connections causesrotation of turret and horizontal swing of gun to any desired extent.

The control of gun elevation, or up and down swinging may be effectedfrom the same handwheel 21 as follows. The handwheel is shown mounted atthe lower end of, a depending carriage or swinging bracket 28; the upperend of which is formed as a yoke-'29 straddling the shaft 23 andconnected to the two parts of a crossshaft 30, which constitutesarockshaft mounted on ears at opposite sidea of the turret. By thisarrangement the swinging of the depending bracket and handwheel causethe rocking of the shaft 3|, and this motion is utilized to vary theelevation of the gun. The connecting mechanism is shown as comprising arockarm 3| extending inwardly from the rockshaft 33, the end of the armbeing connected by a vertical link 32 with an inwardly extending rockarm33 on the shaft I! of the gun. When therefore the handwheel is bodilyswung this changes the gun elevation, while the rotation of thehandwheel swings it laterally with the t et.

The operation of the invent on has thus been fully disclosed upon theillustrative embodiment which affords the objects and advantageshereinbefore set forth.

What is claimed and desired to be secured by United States LettersPatent is:

1. For the training-of a gun carried on the rotary gun turret of anaircraft, apparatus comprising means for neutralizing during flight theaerodynamic thrust of the relative wind upon the exposed part of the gunand the turning moment produced thereby; comprising a swingable wingmember having a general shape and size similar to that of the gun, andprotruding from theturret to a similar degree but oppositely, and amechanical connection between said wing and the gun operatively couplingthem in conjugate relation whereby the force of the wind thrust on thewing in either direction is transmitted and impressed as a turningmoment or torque upon the gun in substantially balanc ing opposition tothe existing turning moment impressed directly on the gun by therelative wind, in the varying positions of gun and wing. 2. Apparatus asin claim 1 and wherein are toothed gears or segments positively gearingthe gun and wing to swing in opposite directions on the turret.

- E'ITORE LANCIANI.

